Where does all the rain come from? It can't all come from the clouds, or they would be empty. No, it is part of a cycle - and the rain goes back up into the sky to fall again and again. This process is called the rain cycle. It involves evaporation and condensation.

Rain falling from the sky enters rivers and streams. It flows down to the sea, losing water all the time through evaporation - particles of water float up into the sky. The water evaporating from the sea condenses to form clouds, and these float inland. When they cross hills, they go higher and higher and the tiny droplets of water come together to form drops that fall as rain. They enter the rivers and the whole process begins again.